Theoretical investigation of microstructure evolution and deformation of zirconium under neutron irradiation

The radiation growth of zirconium is studied using a reaction-diffusion model which takes into account intra-cascade clustering of self-interstitial atoms and one-dimensional diffusion of interstitial clusters. The observed dose dependence of strain rates is accounted for by accumulation of sessile dislocation loops during irradiation. The computational model developed and fitted to available experimental data is applied to study deformation of Zr single crystals under irradiation up to hundred dpa. The effect of cold work and the reasons for negative prismatic strains and co-existence of vacancy and interstitial loops are elucidated.